Materials for use in tumbling barrel polishing and finishing and method of producing same



Patented May 11, 1943 Tirso srrss MATERIALS FOR USE IN TLmG BARREL POLISHING AND FINISHING AND METHOD OF PRODUCING SAME William G. Balz, Kalamazoo, and Leo Richard orric Davidson, Sturgis, Mich.; said William G. Balz assignor to Louise M. Balz, Kalamazoo, Mich.

No Drawing. Application October 20, 1941,

Serial No. 415,828

4- Claims.

Cir

polishing of non-metallic parts which-is highly efiicient and results in a satisfactory polish or points and edges and in that condition are undesirable for the practice of our method and we therefore subject the same to a process for eliminating these sharp points and edges without, however, destroying the irregular outlines of the fragments.

The processing procedure preferably comprises the loading of a many-sided tumbling barrel with the limestone fragmentswith enough water to submerge the fragments, and adding thereto a 1 severe abrasive compound. For a standard size barrel, the following is a satisfactory compound:

fi h Pumice 10 lbs. ms Soap 1 lb.

Thlrd. o provide a material for the purposes Rouge m stated and having these advantages which is very u n 3 pints economical in its initial cost and very durable and also economical in use from the standpoint of time required for the polishing operations.

Fourth, to provide an aggregate material for tumbling barrel finishing and polishing which is highly effective on work of varying sizes, shapes and configurations.

Fifth, to provide a method of preparingpolishing material which is highly desirable for use in dry polishing processes.

Ourpresent invention relates to a dry polishing process for metallic parts or articles, being in some respects similar to the subject matter of our application relating to wet polishing processes and materials used therein covered by our application, Serial No. 415,774, filed October 20, 1941, filed concurrently herewith.

The polishing aggregate of our invention has various characteristics which enables us to accomplish the various stated objects and other objects which will hereinafter appear.

The method of our application comprises two steps although it should be understood that both in the general limits stated. As received from the quarry or stone cutter or as results from crushing limestone, these fragments have sharp that is, sufficient water is used to enable mixing thecompound. This is added to the barrel and the barrel. is revolved for. about 48 hours, after which the water and the abrasive mixture is drained from the fragments and the fragments flushed with clean water. In this prepared form v the fragments are comparatively smooth-sided although their irregular shapes and sizes are not destroyed.

This tumbling barrel aggregate may be used in the tumbling mixtures employed in the roughing or first step of our dry polishing method and also in the second step of our wet polishing method described in our application filed concurrently herewith.

However, for the second step of the method of the present application, the limestone fragments process, as above'described, are further processed by loading a standard type-of dry" burnishing tumbling barrel with the fragments and a so-called fineabrasive compound and adding thereto kerosene and stearic acid in substantial quantities. period of a few hours afterwhich time additional lubricant is added until the limestone fragments have apparently absorbed all the kerosene and need to be added to each tumbling barrel c'oinpartment even when in continuous daily operation and it is not necessary for the added material to have been subjected to the preliminary treatment as the compound used with the aggregate This load is then revolved for a,

preferably contains stearic acid and kerosene as will later appear and in view of the small amount added they do not require the second step in the preparation of the fragments.

The dry" process of our invention is highly useful in the polishing or burnishing of parts which do not require the removal of large quantitles of the material in order to produce the smoothness and polish desired and it is primarily designed for use on stampings or die castings which are in reasonably good condition. The process has the further advantage that it is relatively clean and economical and requires no I drainage as is the casewith our wet process.

As an example of the practical use of our process, we employ a tumbling barrel having two compartments. Each compartment is loaded with 200 pounds of our aggregate above described with the abrasive compound and other materials which may be the same as that disclosed in our copending application Serial No. 330,468, as follows:

Hardwood sawdust '75 lbs. Powdered pumice 25 lbs. Powdered oyster shell 12 lbs.

Rouge 1 lb. 7 ozs. Stearic acid 5 lbs. Kerosene 5 quarts It is found in practice effective to use 52 lbs. of old or used compound and 16 lbs. of new or unused compound although it is obvious that initially a new compound of the same quantity would be used.

The parts to be burnished or polished are then loaded into the compartments, the load depending upon the size, weight and shape of the parts to be operated upon. It may vary greatly but the parts to be polished should be well surrounded by the aggregate and the same is thoroughly mixed. The barrel is then revolved from 24 to 48 hours although the time element is controlled by the finish desired. After a proper time has elapsed to secure the desired finish, the mass including the work is dumped into a suitable shaker or grader which separates the fragments, compound, and work. The barrel is then recharged with the same fragments along with the old compound and new compound as described and the operation may be repeated. From time to time additional aggregate is added. By using a portion of the old compound together with the new compound, substantial economy is effected and the cutting or grinding action is less severe.

When it is desired to produce a high finish or luster, the same machine or types of machines may be used but instead of the compound described for the initial step, the following compound is found to give very satisfactory results- Theproportions we have given may be variedconsiderably and still attain very satisfactory results and, further, it will be appreciated that a other types of compounds may be used, depending somewhat on the character of the articles which are to be burnished or polished and the finish desired. However, the method of our invention may be very efl'lciently practiced following the proportions and materials as indicated, and it results in great economy of materials inasmuch as the aggregate is inexpensive and is very eflicient so that the desired results are very rapidly and inexpensively attained both in the matter of materials and time and also the very great durability of the aggregate.

It should be understood that the terminology we have used herein is used descriptively rather than in a limiting sense and with the intention to include equivalents of the features shown and described within the scope of the following claims.

Having thus described our invention, what we clagm as new and desire to secure by Letters Paten is:

1. The method of treating limestone fragments of widely varying irregular outlines and widely varying sizes which are in substantially the condition resulting from the fracturing of the limestone which comprises tumbling such fragments in the presence of an abrasive until the sharp points and edges have been removed therefrom without destroying the irregular outlines thereof, washing thesame to remove the abrasive and thereafter subjecting such fragments to tumbling in the presence of an abrasive and an emulsiflable oil until a substantial amount of the oil has been absorbed by the fragments and they have smooth surfaces.

2.'The method of treating fractured limestone fragments of widely varying irregular outline which are in substantially the condition resulting from the fracturing of the limestone comprising the steps of tumbling such fragments in the presence of an abrasive until the sharp points and edges have been removed therefrom without destroying the irregular forms thereof, washing the abrasive therefrom and thereafter tumbling the fragments in the presence of an emulsifiable oil until substantial amounts of the oil have been absorbed.

3. A material comprising fragments of crushed limestone of widely varying irregular outlines corresponding substantially to the condition resulting from the fracturing of the limestone and ranging in size from approximately one-half to one and a half inches and having the sharp points and edges thereof removed without destroying their irregular shapes, and having substantially smooth surfaces and a substantial amount of absorbed emulsifiable oil.

4. A material comprising fragments of crushed limestone of widely varying irregular outlines and sizes substantially as resulting from the fracturing of the limestone but with the sharp points and edges thereof removed and the surfaces substantially smooth and impregnated to a substantial extent with an emulsifiable oil.

WILLIAM G. BALZ. LEO RICHARD DAVIDSON. 

